1. Technical Field
The present invention relates to a radiation curable ink jet composition and an ink jet recording method using the composition.
2. Related Art
In recent years, a radiation curable ink jet composition that is cured by being irradiated with radiation has been used in an ink jet recording method for the purpose of forming an image with high waterproofness, high solvent resistance, high scratch resistance, and the like on a surface of a recording medium. Typically, the radiation curable ink jet composition is configured of a polymerizable compound such as a monofunctional monomer or a polyfunctional monomer and an organic material such as a photopolymerization initiator. Therefore, one of important issues of the radiation curable ink jet composition is to reduce odor of printed, cured, and dried image.
For example, JP-A-2007-321034 discloses an ultraviolet curable process color jet ink that exhibits an excellent curing property and excellent adhesiveness to the recording medium and generates less odor from the printed image by a combination of various photopolymerization initiators with low volatility that generate less odor from the printed image after curing and drying.
JP-A-2015-14009 discloses an ink jet ink that generates less odor in a printing stage and during use by an end user without degrading flexibility by containing at least 50% by weight of trimethylolpropane formal acrylate (CTFA) such that the content of high Tg monomer is less than 5% by weight.
However, the ultraviolet curable process color jet ink disclosed in JP-A-2007-321034 cannot reduce odor of the ink itself though it is possible to reduce the odor of the printed image. Therefore, there is a concern of unpleasant odor filled during printing and health hazard of an operator or the like. In contrast, the ink jet ink disclosed in JP-A-2015-14009 cannot secure coating film hardness due to insufficient glass transition temperature (Tg) and cannot secure a sufficiently low odor property of the printed image due to appearance of an unreacted monomer or a decomposition product of the initiator from the surface of the coating film.